I just installed a set of the HotGrips on mine last month. They are awesome! Now, I will never have a bike without heated grips.
http://www.hotgrips.com/sportbike.html
Hot Grips are 1-7/16" outer dia., and the stock grips are 1-1/4" outer dia.
I too like the larger diameter. The rubber in them is slightly harder than stock.
Riding with the temps down into the 50's, low setting is great with some basic uninsulated leather gloves. The comfort difference is incredible.
On the web site, they now sell some gloves that are insulated on the back side to cut wind chill, but not on the face, so that the heat can radiate through them. I plan on ordering and trying out a pair.
They work great with an NEP CC3 throttle lock, and I just had to use one of the spacers. You can get the longer grips and use the spacers, or even ditch the bar ends and have closed grip ends. Boring a hole in the end of the grips is optional.
I think the Throttlemeister works, if you buy the short stock length grips.
It is discussed on their site.
Another brand, by Oxford Products has a 1-5/16" outer dia., available here:
http://www.lockitt.com/AccessoriesGrips3.htm
These only come in 4 7/8" length, but the 1/8" lip on the outer end could be trimmed so they have a stock length to work with the Throttlemeister. Their softness of the rubber is probably closer to stock, but they have more texture, so give a good grip.
Steve